HCA is a naturally-occurring derivative of citric acid found in the fruit of members of the plant genus Garcinia. Free HCA, calcium, magnesium and potassium salts of HCA, and poorly characterized mixtures of two or more of these minerals have been sold in the American market, the calcium- and sodium HCA salts since 1994. Most of the commercial preparations of HCA sold to date consist of calcium salts of varying degrees of purity or, more recently, poorly characterized mixtures of calcium HCA and potassium HCA salts.
HCA can affect the metabolism of mammals, including humans. HCA, as well as several synthetic derivatives of citric acid, can inhibit the production of fatty acids from carbohydrates, suppress appetite, and inhibit weight gain (Sullivan et al., American Journal of Clinical Nutrition 1977; 30: 767). Numerous other benefits have been attributed to the use of HCA, including, for example, an increase in the metabolism of fat stores for energy and an increase in thermogenesis (the metabolism of energy sources to produce body heat in an otherwise wasteful cycle).
The therapeutic use of HCA salts has been limited, however, by their poor absorption and chemical instability at acidic pH, e.g., inactivation of HCA salts via lactonization upon exposure to the acidic milieu of the mammalian gut. HCA in either its favored form for biological availability, as the potassium HCA salt, or in its secondarily favored form for biological availability, as sodium HCA salt, is extremely hygroscopic. As such, HCA in its more biologically active forms can be only be maintained as a powder under well-controlled dry conditions. There remains a need for soluble HCA-containing compositions suitable for inclusion in dry delivery formats, liquid delivery, and in controlled-release vehicles.